Stroke 1/12/15 Flashcards
1
Q
Stroke Risk Factors
A
- Untreated AFib
- Hypertension
- Smoking
- Hyperlipidemia
- Diabetes Mellitus
- TIA (Transient Ischemic Attack)
- Previous Stroke
- Heavy alcohol consumption
2
Q
Transient Ischemic Attack (TIA)
A
- Common causes: embolism & stenosis-related hypoperfusion
- Examine arterial supply, cardiac, and hypercoaguable state
3
Q
Stroke can be characterized as:
A
- Ischemic (88%)
2. Hemorrhagic (12%)
4
Q
Causes of ischemic stroke
A
- Arteriosclerotic (large vessels)
- Embolic (24% of all strokes, affects medium vessels)
- Lacunar (small vessels)
- Amyloid deposits (microcirculation)
- Hypoperfusion (border zone)
5
Q
Anterior circulation
A
- Middle cerebral
- Anterior cerebral
- Posterior communicating
6
Q
Posterior circulation
A
- Includes PICA, anterior and posterior spinal arteries off vertebral
- All branches off basilar
- Posterior cerebral artery
7
Q
Conditions that influence progression and extent of ischemic injury
A
- Rate and duration - fast onset & long duration is worse
- Collateral circulation
- Systemic circulation - want adequate systemic BP to maintain circulation
- Coagulation - hypercoaguable state increases progression and extent, exacerbating vascular occlusion
- Temperature - increased body temp is associated with greater ischemic injury
- Glucose - hyper and hypoglycemia have negative effects of ischemic injury
8
Q
Normal cerebral blood flow (CBF)
A
50 to 60 ml/100gm/minute
9
Q
Penumbra
A
- Electrical silence and synaptic activity greatly diminished to preserve energy stores
- Reversible
- CBF reduced to below 20 ml/100gm/minute (which is 25-50% of normal)
- “Window of opportunity”
10
Q
Ischemic Core
A
- Irreversible neuronal injury with CBF less than 10 ml/100gm/minute
11
Q
Causes of cell death
A
- Noxious metabolites from injured neurons
- Breakdown of blood brain barrier
- Excitotoxicity
- Apoptosis
12
Q
Factors associated with red infarcts/hemorrhagic transformation of stroke
A
- Size of infarct
- Richness of collateral circulation
- Use of anticoagulants and interventional therapy with thrombolytic agents
13
Q
Large vessel disease
A
- Most common disease process: arteriosclerosis
- Mostly occurs at bifurcation of vessels
- Not a significant blockage until > 70%
14
Q
Medium vessel disease
A
- Most common pathology: embolism
- Most common cause: Afib
- Can affect proximal (more devastating impairments) or more distal part of vessels
15
Q
Small vessel disease
A
- Most common pathology: Lacunar
- Can affect penetrating vessels & distal small vessels that usually affects deep white matter area (including internal capsule)
